Microsoft 365 Alert – Service Degradation – Exchange Online – Some users may be unable to send email messages from mailboxes through the Exchange Web Services (EWS) API – RESOLVED

Announcements Habiba Tabasum

05/06/2024 08:32:00 AM

NHSmail reference: INC43483967

Microsoft Reference: EX798632

Issue Status: RESOLVED

Issue Description: Users may be unable to send email messages from mailboxes through the EWS API.

Final Update: 06/06/2024 09:00:00 AM – Microsoft validated with a set of test users that the fix is operating as expected and deployed the change broadly to all impacted users. After a period of monitoring service health subsequent to the completion of the broader deployment of the fix, they’ve confirmed with affected users that this issue is resolved.

Scope of impact: Some users attempting to send email messages from mailboxes using the EWS API are affected.

Root cause: A recent update to the components of Exchange Online infrastructure responsible for sending email messages from mailboxes through the EWS API introduced a misconfiguration that’s leading impact.

Next steps: Microsoft are reviewing their validation and update procedures to detect and prevent issues like this prior to deployment in the future.